


To Kill A King

by shadowglove88



Category: Merlin (TV)
Genre: Cunning Mordred, Established Merlin/Arthur Pendragon, F/F, Implied Sexual Content, M/M, Obsessive Mordred, One Shot, One-Sided Attraction, Season One Spoiler: The Beginning of the End, Top Arthur
Language: English
Status: Completed
Published: 2018-09-09
Updated: 2018-09-09
Packaged: 2019-07-10 09:56:58
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,491
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15946985
Author URL: https://archiveofourown.org/users/shadowglove88/pseuds/shadowglove88
Summary: Mordred was 14 when Merlin and Morgana escaped to the Isle of the Druids, and Mordred fell in love. Then he witnesses a secret encounter between Merlin and Arthur that ignites the beginning of the dragon's warning to Arthur: the beginning of the end.





	To Kill A King

**Author's Note:**

> As always - this is an oldy.
> 
> Note: I couldn't find a reason for Mordred to want to kill Arthur after "The Beginning of the End", but the Great Slash Dragon warns its cannon, so I gave Mordred my own reason!
> 
> Note2: Inspired by the great babydracky , whose Mordred/Merlin stories I adore.

Mordred was fourteen when Merlin and Morgana escaped Camelot and found their way to the Isle of the Druids.

Many years had passed since Mordred had been spirited out of Uther’s kingdom, but those days had never blurred in his memory. He remembered the searing pain in his arm from the sword injury, he remembered the drowsiness from the fever that’d taken over him, and he remembered Merlin’s comforting presence encircling him during the whole time. Despite the fear that’d consumed the boy child during his harrowing days in the castle, he’d felt safe because he was in Merlin’s care, and Merlin’s voice in his head soothed him unlike anything else.

Morgana had also proven herself to be a worthy ally, risking her own life to get him to freedom, and then she’d convinced the Crown Prince himself to risk saving Mordred from the prison and sneaking him out of the castle to the druids waiting deep in the forest.

This act of mercy from the Crown Prince of Camelot had shaken Mordred’s every belief, but while he was forever in debt to Arthur, the child couldn’t help but resent him. Even as the blonde was drawing his sword to protect him, Mordred had resented him because he knew that while Merlin had risked his own life and stayed by his side, that the man,  _Emrys_ , was hesitating now to save him.

And he knew somehow that it was because of the prince. The moment Arthur had gotten involved Merlin had nearly left them to be found. Mordred had used the telepathic connection he had with Merlin, feeling how the older male  _wanted desperately_  to help but didn’t because he felt it was better for  _Arthur_ \-----and Mordred had  _hated_  Arthur.  _Hated_  how Merlin would choose his life over Mordred’s.

What was so wonderful about this prince?

And yet, despite it all, Merlin had listened to Mordred’s pleadings and come to rescue them.

Mordred had wanted Merlin to take him to his people, for Merlin to go with him, and yet he hadn’t spoken a word because the prince was there, instead whispering to Merlin’s mind. He tried to get the older male to see that if he stayed here he’d be hunted just as Mordred was being hunted, but his pleadings were interrupted as the bells rung---their escape had been noticed.

In seconds Arthur had thrown him up onto a horse and gotten up behind him, galloping away after warning Merlin to get to safety so that he wasn’t suspected.

Arthur had then taken Mordred to his people, and Mordred had been returned to his home of the Isle of the Druids. There he was safe, and taught magic, studied more fervently the texts and scrolls concerning Emrys. The druids had been surprised when he’d asked to be taught how to fight with weapons as well, not only magic, and they found someone to teach him.

He applied himself to his studies with the fervor no child ever should, learning how to kill with weapons forged of man, and with the power within his own body. As prophesied before his birth, Mordred was already becoming the greatest druid, his people’s greatest warrior.

And he was still only pubescent.

But no one could understand his dedication, or what drove him.

They didn’t understand that what he’d shared with Emrys had been intimate and deep, their minds and souls has touched, their magics had connected during his short stay in Camelot. It’d been unlike anything Mordred had ever experienced, and he craved it again desperately. He desired the swirl of magic in the pit of his stomach whenever Emrys would speak to his mind.

Mordred had always had the ability to project his thoughts into other people’s minds, to sense them, but this was the first time it’d been reciprocated.  _Finally_  he’d found someone powerful enough to not only match the potential, raw magic within him, but who clearly  _surpassed_ him.

He knew that Merlin had felt it too, the nearly  _addictive_  taste of their powers combining, flowing silkily one through the other, he  _knew_  that it must have given Merlin the same pleasure. And yet every night since his return to his people Mordred tried to reopen that channel, to speak to Merlin, and every night Emrys ignored him, ignored his calls, his pleading.

Mordred had felt Merlin’s desire to answer him, but he’d also felt the feeling warring with Merlin’s own desire to protect the prince, and while Mordred didn’t understand what one feeling had to do with the other he understood that the reason Merlin was forsaking him was because of Arthur...

...And that dark resentment that already lay in Mordred’s heart against the prince continued to grow, to fester.

News of Morgana’s imprisonment due to being a ‘witch’ reached Mordred’s horrified ears years later, when he was fourteen, and he remembered the beautiful woman who’d taken care of him like a mother. How could the King plan on executing his own ward?

Mordred, fury building deep within him, had told Merlin that he was returning to Camelot, and he’d kill  _everyone_  in the castle other than Merlin and Morgana.

It wasn’t even a day later when news of the Prince’s own Manservant outing himself as a warlock and saving Morgana from the prison cell reached Mordred’s ears. According to the newcomer druid with the news, Merlin and Morgana had disappeared, but that Uther was furious and had a large bounty on both of their heads.

 _Emrys_. Mordred had reached out to Merlin.  _Come to the Isle, you and the Lady Morgana will be safe here._

He didn’t get an answer, didn’t know what Merlin would do, and then days later a canoe of foam had made its way over the misty water and two figures sat on it.

Merlin, eyes glowing molten gold, and a pale yet relieved looking Morgana looking up at them.

They’d both been welcomed by the druids and made at home.

Mordred had hugged Morgana close, half-listening to her gasps on how much he’d grown since she’d last seen him, on how he was turning into a handsome young man. It wasn’t that Morgana’s words didn’t mean anything to him, but Mordred truly couldn’t have been expected to put his full attention on anything that wasn’t Emrys at the moment.

He---he looked just the same as Mordred last remembered him.

Morgana was still breathtakingly beautiful, but you could tell that age had touched her with its cold hands.

Merlin on the other hand looked like he hadn’t aged a day.

 _It is good to see you again, Emrys_. Mordred’s eyes met Merlin’s, who was eyeing him warily.  _It is good that you are here. You and the Lady Morgana will find this a simple but pleasant home_.

For a moment he thought that even face to face Merlin would ignore his whispers in his mind, and then the warlock smiled and shook his head. "Is it that you prefer to speak mentally or are you just too lazy to use your mouth when around me?"

Mordred fought the blush as he thought of all the things he could do with his mouth while around Merlin, instead managing to look unaffected by the unintended innuendo.  _Our words are private, Emrys. They are intended only for you and me._

Merlin tilted his head slightly and observed him thoughtfully at that before turning his attention back to Morgana.

Mordred couldn’t help but feel cold and slighted as Merlin spent the next couple of weeks seeing to Morgana, acting more as her personal servant than the great warlock they all knew him to be. The older man barely spoke to Mordred, seemed to even be  _avoiding_  him, and Morgana seemed all that he could see, all that he cared about.

It angered Mordred, and he did his best to give the warlock the same treatment, but the druid lost that battle long before he even began, and found a way to Merlin through Morgana. The closer he got to the woman, the more in her favor he was, the more time he spent with Merlin---the more the warlock fascinated him.

And finally, after what seemed like an eternity, Merlin let down his guard while around Mordred and gave him the first  _truly genuine_  smile ever.

And that was when Mordred realized that he’d fallen in love with Merlin. Maybe it’d developed from his possessive childish feelings, or maybe he’d always been in love with the warlock. He wasn’t exactly sure which, but that didn’t matter, did it?

Merlin was now here on the Isle with him, and that was how destiny worked.

There was no other explanation for this in Mordred’s mind.

Merlin was  _meant_  to be his.

It was only a matter of time.

“Cadmus has asked for my blessing, he’s going to ask for Morgana’s hand,” Merlin admitted to Mordred as they sat together, clapping along to the music and laughing as the people enjoyed themselves as they danced around the fire. “I don’t understand  _why_  he asked for my blessing, and I told him this. I have nothing to do with the whole thing.”

“Morgana is your ward, Emrys. You protect her dearly.” Mordred, now a year older, smiled at the man whose height he now matched. He was sure in a year or two he’d surpass the warlock in height, and that made him quite proud. “No one will dare approach her for marriage without first seeking your blessing.”

“Oh.” Merlin blinked, surprised. “I hadn’t realized that.”

“Do you think she will accept his offer?” Mordred asked, not exactly sure he wanted Cadmus for Morgana. His gaze went to where the older man was watching Morgana dancing with the other women, her face radiant, his pathetically besotted.

“No.” Merlin didn’t hesitate as he shook his head. “She belongs to another, heart body and soul.”

Mordred turned back to Merlin at that, frowning in confusion. “She does?” He narrowed his eyes. “It is not the Pendragon prince, is it?”

“Gods no!” Merlin snorted in laughter at that and clapped Mordred on his back. “You truly were a child when you were in Camelot if you ever thought those two could have feelings for each other that weren’t platonic!”

That was obviously a  _no_ , and Merlin was obviously making fun of him, but Mordred couldn’t be angry, not when Merlin left his hand there on his back when he turned to look at the dancing.

Mordred just smiled and shifted slightly closer to the warlock, more than sure that Merlin hadn’t noticed that he’d left his hand there or that they were much closer now, or that people were watching them with knowing, approving glances.

His face was pleased the whole celebration, and he even managed to convince Merlin to get up and dance a couple of dances with the men. The air around Merlin crackled with golden magic, and yet it was Merlin’s lips and the sound of his laughter that entranced Mordred, that left him spellbound and feeling completely  _helpless_.

It was due to the fact that he seemed unable to look away from Merlin, to not  _feel_  him magically, to not notice his every movement, that when everyone else were staggering and drunk Mordred noticed Merlin tensing.

The warlock’s eyes flashed gold and then he stood, walking away hurriedly, face determined and hopeful.

Mordred, confused and wary, followed behind Merlin, followed him to the shore of the Isle of the Druids, looking out at the water one couldn’t cross if not invited.

Merlin conjured his canoe of foam and crossed the water, Mordred following behind in one of the enchanted canoes of woods his people used. He kept hidden in the mist, following his prey, until Merlin came upon two strangers in the black of the forest, hidden in cloaks.

Mordred’s eyes narrowed, ready to summon his power if needed, but then there was a cry and the smaller figure threw itself at Merlin and… _they hugged_.

The hood fell off of the figure to reveal dark skin and darker curls as the woman held onto Merlin and hugged him tightly.

Merlin hugged the woman but his gaze was on the taller figure still covered by his hood. “What are you two doing here? If Uther ever found out---.”

“Leave father to me.” That voice Mordred remembered all too well rumbled, and the hood was lowered to show Prince Arthur in the moonlight, looking at Merlin with intense happiness and relief. “How are you, Merlin?”

“ _Arthur,_ ” Merlin whispered, his voice a prayer.

Mordred took a step backwards at the adoration in that one word.

“How is Morgana?” The woman asked, stepping out from Merlin’s hold. “Is she well? Have her nightmares continued to torment her?”

“She’s fine. I’ve been taking care of her the best I could for you.” Merlin smiled down at the woman tenderly, but not in the way he’d smiled at  _Arthur_. “If I had known that you were here I would have brought her with me.” His smile fell. “She has missed you terribly, Gwen.”

“And I her.” Gwen’s voice trembled as she wiped at her eyes. “But I’m here now, and I’m not leaving.”

Merlin’s eyes widened. “What are you saying? Gwen! If Uther finds out you will never be able to return to Camelot---.”

“My place is by Morgana’s side,” Gwen interrupted, determined. “If I had known you were a warlock and would rescue Morgana that night I would have begged you to take me with you since then.” She closed her eyes tightly. “Please, I  _need_ to be with her.”

Merlin looked at her, looked at Arthur, and then looked back at Gwen and nodded. “I will take you to her.”

Gwen’s eyes widened and she smiled tearfully at him. “ _Thank you_ , Merlin.” She turned to Arthur. “And thank  _you_  sire. I, I will go wait by the shore.”

Mordred glared at her back as she gave the two men the solitude he’d been wishing them never to have. There was something about the way they looked at each other that made him both cold and blazing hot all at the same time.

Merlin nor Arthur spoke, but they moved at the same time, mouths connecting and hands grabbing at clothes, hair. Their actions were desperate and needy as Arthur pushed Merlin up against a tree and began whispering things against his skin as he nibbled hungrily on his neck.

Words like ‘I love you’ ‘I miss you’ ‘I don’t want to leave you’ and ‘you truly  _are_  the worst manservant I’ve ever had’.

Merlin laughed, and it was a choked sound due to the tears falling as he whispered the same words back to Arthur, adding a ‘Prat’ that sounded too much like an endearment to Mordred.

The druid watched as lips smashed together, hands grabbed, breeches were lowered, and Merlin’s throaty groan as Arthur entered him was torture. And yet Mordred didn’t move, couldn’t look away. He forced his eyes to focus solely on Merlin, greedily, amazed at the sounds Merlin made, at the expressions on his face, at the way his mouth would open and yet no sound came out---and then he’d let out the lustiest moan…

It was over almost as soon as it’d started, both spent and crying into each other’s mouths, holding each other tightly, not wanting to let go.

They collapsed on the ground, Merlin curled up into Arthur, who held him tightly, possessively, held him like Mordred wanted to.

“I don’t want to let you go,” Arthur whispered, voice choked, tightening his hold on the thinner, paler man. “I don’t want to go, to leave you, I won’t be able to bear this separation much longer Merlin.”

Merlin closed his eyes tightly, lips trembling as he held on tightly as well. “When you’re king, you will right this, Arthur. When you’re king, and magic isn’t banned, I will come back,” he promised, pressing a kiss to Arthur’s heartbeat. “The moment that crown rests upon your head, I will return. I swear it to you upon my life.”

Mordred went cold in horror as those words left Merlin’s lips. Then his eyes narrowed in vile hatred at the one person who would be taking Merlin away, who had  _always_  been between him and the warlock.

“I will make you my Queen,” Arthur vowed.

 _You will_ _ **never**_ _have him again_. Mordred made a vow himself, eyes nearly glowing in his anger.

“How about Advisor?” Merlin laughed. “I don’t think Camelot is ready for a male Queen, not yet at least. And you  _must_ think about heirs.”

“I don’t  _care_  about heirs,” Arthur hissed. “I’ll make a relative my heir, or a knight or lord who proves himself worthy. But I will  _not_  marry, Merlin, unless it’s  _you_.”

Merlin smiled tenderly and closed his eyes. “Nor I unless it’s  _you_.”

Unable to hear anymore without giving away his presence due to his rising fury, Mordred stormed away, and stayed away from the Isle for a whole month.

He spent the time in the forest, communing with nature, meditating, trying to understand what he must do.

All he knew for sure was that Merlin would never be with Arthur again.

He wouldn’t allow it.

He  _couldn’t_  allow it, couldn’t allow Merlin, his magic, his  _body_  to be polluted and corrupted by  _Pendragon filth_.

It was during his stay in the deep of the forest, during a three-day meditation, that Mordred received the vision, received the knowledge, and knew what must come to pass.

With this knowledge he returned to the Isle, and noticed that in his absence not only had the druids accepted the kind and sweet Gwen, but that she’d gone through a Hand Fastening ceremony with Morgana.

He’d never seen the noble woman as happy as she was now that her beloved was with her once again, and  _hers_  in the eyes of the people.

And he knew, he  _knew_  that one day he’d look at Merlin and Merlin would smile that smile for  _him_.

He  _knew_.

Things just had to happen before then.

“We were worried about you, you know,” Merlin announced as they stood by the shore, looking out upon the water. “You just disappeared. We thought something had happened to you.”

 _Did you worry about me, Emrys?_  Mordred didn’t bother speak. He hardly ever spoke to Merlin verbally anymore, instead preferring to remind the warlock of how they were connected, even if Merlin failed to admit just  _how connected_  they truly were.  _Would it make you sad if something evil befell me?_

“Of course it would!” Merlin looked surprised, hurt, and a little offended. “You’ve become a close friend of mine, Mordred. I have grown to care for you. I thought you’d realized this.”

Mordred smiled.  _Do not worry about me, Emrys. It is not my fate to die an untimely death, nor will I allow any evil to befall you. I will protect you._

Even from Merlin himself.

Merlin gave him an amused and confused smile. “I’m not a bloody  _girl_  in need of defending, Mordred. You know that.”

 _I will protect you._  Mordred pressed, wanting Merlin to know that Mordred protected what was his---or what  _would_  become his, with time and patience and great cunning on his part, in the future.

Merlin smiled tenderly.  _I believe you_.

Mordred smiled back and wondered if Merlin realized that for the first time since he’d rescued Mordred in Camelot, he’d responded to him in his mind. _I must go study._

Merlin nodded his understanding.  _You’ve been studying hard lately, completely dedicated to your trainings and your books._ He tilted his head to the side.  _What prompted this?_

 _I found the incentive I needed to continue on_. Leaving it at that, Mordred turned and left Merlin watching his back curiously.

He couldn’t tell Merlin that he knew Arthur would soon be crowned King of Camelot, or that he knew that Merlin would leave to join the king as soon as the crown was placed upon his golden head.

He couldn’t tell Merlin that the druids would make a peace treaty with Camelot, or that he would be sent there as their Ambassador. He couldn’t even tell Merlin that the dragon he would set free wouldn’t be as benevolent as it had appeared to be.

No, Mordred couldn’t tell Merlin this because then the warlock would want to know more, know how Mordred knew, and the druid couldn’t say any more. He couldn’t tell Merlin of the future, nor of his own part in it.

So Mordred steeled his shoulders, steeled his  _determination_ , and headed towards where his tutors were waiting to teach him all he needed to know.

And somehow, somewhere between the pages of the ancient tomes and the words of wisdom of his ancestors, he’d learn just  _how_  to kill a king.


End file.
